''I was not elected by the factional leaders of the ALP to do a job. They may be doing a job on me,'' he said.

In an attempt to salvage votes, Mr Rudd promised to bring a speedy conclusion to the mining tax saga and initiate a timetable to implement an emissions trading scheme.

After being pressured to take a hard line against asylum seekers, he baulked, saying he would not engage in a race to the right.

The push to oust Mr Rudd was led by the Victorian senator David Feeney, the Victorian MP Bill Shorten, and the South Australian senator Don Farrell, all right-wing heavyweights. Sources said they met Ms Gillard yesterday afternoon in an attempt to persuade her to stand. She was reluctant.

Senator Arbib and Ms Gillard were instrumental in forcing the government to abandon the emissions trading scheme, which was the catalyst for the government's slide in the polls.

The move against Mr Rudd was sparked by a report in yesterday's Herald that Mr Rudd had used his chief of staff, Alister Jordan, to sound out the backbench over the past month on the level of support for him. This followed a Herald/Nielsen poll which showed the government would lose if an election were held then.

But Mr Rudd's action was regarded as a sign that he did not trust the repeated assurances by Ms Gillard that she would not stand. ''It was offensive and disloyal,'' said a Gillard supporter.

Ms Gillard, who all day had resisted overtures to mount a challenge, visited Mr Rudd in his office at 7.20pm.

Senior ministers came and went while Ms Gillard, Mr Rudd and Senator Faulkner discussed the crisis. It was understood Ms Gillard was reluctant to have a messy challenge and other options were for Mr Rudd to stand aside, or try to save his leadership by agreeing to policy and organisational changes. But he refused and decided to fight.

''If Gillard runs, she'll be the prime minister,'' said one operator.

The Trade Minister, Simon Crean, who is close to Ms Gillard, called for calm and tried to stop a challenge.

Another Left powerbroker feared that unless Mr Rudd stepped aside willingly it would tear the government apart and destroy its already diminishing election prospects. ''There's no way Kevin will walk. The bloke's wanted the f---ing job for 10 years,'' he said. ''Howard had it for 11 years and they couldn't get rid of him.''

Only six months ago, with the opposition undergoing its third leadership change since the election, Mr Rudd and his government appeared unassailable. But even if he survives the latest push, his leadership and the fortunes of the government will have been damaged.

Mr Rudd is scheduled to leave for Toronto, Canada, tomorrow for a Group of 20 leaders' meeting and has a meeting scheduled with the US President, Barack Obama.

Today would be the last day for the rebels to mount a challenge because Parliament will rise for the eight-week winter break and many expected Mr Rudd to call an election before the Parliament returned. A series of policy failures, poor polls and the decision to go to war with the mining industry have all contributed to Mr Rudd's plunging fortunes among his colleagues.

The Coalition fears a change to Ms Gillard. Although she bears responsibility for many of the government's poor decisions, including shelving the emissions trading scheme and the school buildings program, she would be harder to beat than Mr Rudd.

But an Essential Media poll released this week showed that both she and Mr Rudd were preferred above Mr Abbott as prime minister by about the same proportion of voters.